After our honeymoon cruise, we went to WDW for three nights and my new DW said she would be willing to get into DVC. Well, I was taken aback, and we went directly to SSR via the bus system right after we checked into the Swan (it was about 8:30am or so). I start it like this to say we toured and then bought during the same stay.
After getting the tour and our questions answered, we took the info and went to the Swan. After a nice nap (you get up early on
DCL to leave

), we went back to sign our docs.
Here are the advantages we had for signing there that I have yet to hear on these boards:
We signed the docs right then and they were notarized by a DVC rep (ALL paperwork done and nothign lost).
I had bought some breakfast vouchers and Lunch Vouchers on eBay for our trip (BTW, I still have them, so if someone needs them, PM me, 2 each adult versions) but I did not get the Quick and Casual. Since I heard on the DIS that they had some, I asked my sales rep if I could purchase a couple. He left and returned with two for free!
Of course we got the backpack and litho of SSR, but as we were leaving, our guide asked if we were given the FastPass cards. He left and came back with two plastic cards with the DVC logo on them that can be used to get 2 extra fast pass tickets! Thus, I could have a fastpass for Splash Mountain and Space Mountain at the same time! It was a nice little extra we plan to use on our next trip (plus the cards are neat).
They also have van specifically for new DVC customers that will pick you up from wherever and take you to the SSR DVC office and then return to wherever you want later. We used them to go back to the hotel after the first visit then to MK after signing. The drivers would not hear of taking a tip and ours were great!
One thing that was mentioned on here, some guides have given families (especially the children) free SSR pins for their lanyard.
I guess the advantage to going is being able to pick up some freebies along the way!
Good luck!
Oh! Forgot one last thing!! We received a temporary DVC member card after signing that can be used liek the regular plastic one. Thus, the DVC discounts on APs, restaurants, water parks, Disney Quest, etc is available immediately. Also, you can use the card to ask the pin stores to show you the special DVC pins, shirts, or whatever they may have
